Re: Circles of confusion (was UV light sources)
SCHRAMMR@wlsvax.wvnet.edu
Tue, 12 Dec 1995 12:20:25 -0500 (EST)
I can't remember the name of this process, but in involves using a point
source of light, a slide and a camera without a lens in a darkroom. The
slide is placed about 10 cm from the camera with no lens and inline with
the camera and point source. What results is an interesting, distorted
image which is really made up of hundreds of diffraction patterns. My point
is that you cannot get this effect if you: 1. do not use a point source,
2. the slide is not located some distance from the film plane. When I
last worked with this method, I remember that changing the distance between
the slide and the film plane made a big difference in the size of the
diffraction patterns. Bottom line- I'm going to suggest that there would
be no diffraction patterns if: A. the light source is not a point source,
B. there was no seperation between the slide (or negative) and the
photosensitive surface. BTW wasn't it President Bush who invented 1000
points of light? ;-)
Bob Schramm